From owner-freebsd-multimedia@freebsd.org  Fri Dec 20 18:46:10 2019
Return-Path: <owner-freebsd-multimedia@freebsd.org>
Delivered-To: freebsd-multimedia@mailman.nyi.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1])
 by mailman.nyi.freebsd.org (Postfix) with ESMTP id E2C1F1E0CF5
 for <freebsd-multimedia@mailman.nyi.freebsd.org>;
 Fri, 20 Dec 2019 18:46:10 +0000 (UTC) (envelope-from hps@selasky.org)
Received: from mail.turbocat.net (turbocat.net [88.99.82.50])
 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)
 server-signature RSA-PSS (4096 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 47fd4K6QYyz4HC7
 for <freebsd-multimedia@freebsd.org>; Fri, 20 Dec 2019 18:46:09 +0000 (UTC)
 (envelope-from hps@selasky.org)
Received: from hps2016.home.selasky.org (unknown [62.141.129.235])
 (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits))
 (No client certificate requested)
 by mail.turbocat.net (Postfix) with ESMTPSA id 11DDA2602EC;
 Fri, 20 Dec 2019 19:46:02 +0100 (CET)
Subject: Re: [off-topic] Applying gain to an audio sample
To: Marcel Bonnet <marcelbonnet@gmail.com>,
 FreeBSD multimedia <freebsd-multimedia@freebsd.org>
References: <CAPe0dB=BGyeLX3Xue=nNpHqRn8s-4xAO_T4Asmv-DUGk8uu2Jg@mail.gmail.com>
From: Hans Petter Selasky <hps@selasky.org>
Message-ID: <77875a51-0cef-a27f-7d27-9eac8426bb74@selasky.org>
Date: Fri, 20 Dec 2019 19:42:55 +0100
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:68.0) Gecko/20100101
 Thunderbird/68.1.2
MIME-Version: 1.0
In-Reply-To: <CAPe0dB=BGyeLX3Xue=nNpHqRn8s-4xAO_T4Asmv-DUGk8uu2Jg@mail.gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Rspamd-Queue-Id: 47fd4K6QYyz4HC7
X-Spamd-Bar: -----
Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none;
 spf=pass (mx1.freebsd.org: domain of hps@selasky.org designates 88.99.82.50 as
 permitted sender) smtp.mailfrom=hps@selasky.org
X-Spamd-Result: default: False [-5.42 / 15.00]; ARC_NA(0.00)[];
 RCVD_VIA_SMTP_AUTH(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0];
 FROM_HAS_DN(0.00)[];
 R_SPF_ALLOW(-0.20)[+a:mail.turbocat.net:c];
 NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain];
 DMARC_NA(0.00)[selasky.org]; TO_MATCH_ENVRCPT_SOME(0.00)[];
 TO_DN_ALL(0.00)[]; RCPT_COUNT_TWO(0.00)[2];
 IP_SCORE(-3.12)[ip: (-9.32), ipnet: 88.99.0.0/16(-4.72), asn: 24940(-1.56),
 country: DE(-0.02)]; FREEMAIL_TO(0.00)[gmail.com];
 FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[];
 MIME_TRACE(0.00)[0:+];
 ASN(0.00)[asn:24940, ipnet:88.99.0.0/16, country:DE];
 MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[];
 RCVD_COUNT_TWO(0.00)[2]
X-BeenThere: freebsd-multimedia@freebsd.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Multimedia discussions <freebsd-multimedia.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-multimedia>, 
 <mailto:freebsd-multimedia-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-multimedia/>
List-Post: <mailto:freebsd-multimedia@freebsd.org>
List-Help: <mailto:freebsd-multimedia-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-multimedia>, 
 <mailto:freebsd-multimedia-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 20 Dec 2019 18:46:10 -0000

On 2019-12-20 19:43, Marcel Bonnet wrote:
> - read an audio sample as integer (stereo 16 bit LE)
> - convert to float
> - apply a gain, like: sample *= 0.3f
> - convert to integer again

The attachment is missing.

Probably better to use the host endian version of AFMT.

--HPS